Considering the Role of Social Stressors in Chemical Risk Assessment

September 29, 2023 | Ali Aslam

Per- and polyfluoroalkyl substances (PFAS) are a group of human-made chemicals widely used in a variety of applications. They may be present in drinking water, soil, and household and consumer products. Researchers have performed toxicological studies to find that PFAS may pose significant health risks, including adverse effects on the immune system, liver, and endocrine system. In addition to chemical exposure assessments, state and territorial health agencies may also consider the role of social stressors during the risk assessment process.

Social stressors include community-level determinants that can exacerbate health outcomes for affected populations, such as socioeconomic factors, racial discrimination, violence, and job and food insecurity. These factors may also lead to environmental justice concerns when health disparities in communities result from increased vulnerability and/or increased susceptibility. The cumulative health impacts of social stressors can be evaluated by measuring allostatic load, multimorbidity, comorbidity, or other research methods for assessing cumulative impacts. This brief looks at the role of social stressors in environmental epidemiology, provides examples from state agencies, and identifies potential barriers for considering social stressors in risk assessments.

Accounting for Social Stressors in Risk Assessments

Incorporating evaluation of social stressors into risk assessments of PFAS and other chemicals allows researchers to better understand the cumulative impacts associated with certain chemical exposures. For instance, communities with lower socioeconomic status may have greater exposure to harmful chemicals due to the location of industrial sites or inadequate waste disposal practices near historically marginalized communities. Understanding these disparities helps identify vulnerable populations and effectively target risk mitigation strategies. Assessing the impacts of social determinants also allows for a more holistic evaluation of the stressors impacting communities that may already be burdened with harmful environmental exposures. These may include pollution from other industries, socioeconomic disadvantages, and/or limited access to healthcare and nutritious foods.

States Assessing the Role of Social Stressors

A few state agencies have taken steps to consider social stressors as they assess the risks of environmental exposures. The examples below demonstrate how these agencies address environmental justice concerns and aim to protect vulnerable populations:

• The Michigan Department of Environment, Great Lakes, and Energy created MiEJScreen to map population characteristics and environmental conditions to determine census tracts with environmental justice concerns. Michigan’s Department of Health and Human Services also engages communities as part of the Michigan PFAS Exposure and Health Study. This long-term study seeks to characterize the health impacts of PFAS exposure, which can help to inform risk assessments and ensure that potential impacts are adequately considered in decision-making.
• The California Environmental Protection Agency uses CalEnviroScreen, an environmental justice screening method that considers social determinants of health, such as poverty rates, linguistic isolation, and education levels, to identify communities disproportionately affected by exposure to environmental contaminants.
• The Minnesota Pollution Control Agency developed a PFAS Blueprint that discussed the importance of addressing PFAS exposure in over-burdened communities. The agency considers opportunities for collecting data on demographics, income levels, and other social stressors in communities near contamination sites. This approach helps identify populations at higher risk and facilitates the development of targeted risk management strategies.
• The New York State Department of Environmental Conservation incorporated environmental justice principles into its policies and maintains spatial data of potential environmental justice areas. In the state’s Multi-Site PFAS Health Study, researchers collect information on the health effects of PFAS and socioeconomic factors to understand potential disparities in health impacts.

Barriers to Incorporating Social Stressors in Risk Assessments

While accounting for social stressors may improve how agencies can characterize risks of environmental exposures for different populations, it is extremely challenging to carry out risk assessments to evaluate the cumulative impacts of multiple different exposures. There are a few additional key barriers that make this task particularly challenging, including:

1. Lack of Data: Limited available and quality data on social stressors may impede the accurate identification and assessment of communities facing disproportionate impacts. Some federal programs, such as EPA’s EJScreen and CDC’s Environmental Justice Index, aim to bridge the data gap and improve access to spatial data on environmental health outcomes.
2. Institutional Barriers: Some state agencies may lack the frameworks, guidance, or resources to incorporate social stressors into risk assessments. Overcoming these barriers requires dedicated efforts to develop comprehensive methodologies and train and support agency staff.
3. Scientific Complexity: Incorporating social stressors into risk assessments requires multidisciplinary collaboration. Integrating social science, public health, and environmental justice considerations into traditional risk assessment frameworks may be challenging due to the complexity of interactions between chemical exposures and social factors.

Despite these challenges, considering social stressors in risk assessments of PFAS and other chemicals can help to promote environmental justice and address health disparities related to environmental exposures. With concerted efforts and multidisciplinary collaboration, agencies can improve risk assessments, promote equitable protection, and mitigate the social impacts of PFAS and other chemicals of emerging concern.